https://sandpond.cool/Libraries/eatlegacy.js

1
2// This is an older version of the Eat library.
3// I kept it because SpaceTode still uses it.
4
5//
6// Every result has three properties...
7//
8// 'success'
9// true if the desired thing was found
10//
11// 'snippet'
12// the desired thing
13//
14// 'code'
15// the rest of the code (with the desired thing removed)
16//
17
18EAT = {}
19HABITAT.EAT_LEGACY = true
20
21{
22	
23	//====================//
24	// Control Structures //
25	//====================//
26	EAT.many = (func) => (source, ...args) => {
27		
28		// Buffers
29		let success = undefined
30		let code = source
31		
32		// Head
33		let headResult = undefined
34		headResult = {success, code} = func(code, ...args)
35		if (!success) return {...headResult, code: source}
36		
37		// Tail
38		let tailResult = undefined
39		tailResult = {success, code} = EAT.many(func)(code, ...args)
40		if (!success) return headResult
41		tailResult.snippet = headResult.snippet + tailResult.snippet
42		return tailResult
43		
44	}
45	
46	EAT.maybe = (func) => (source, ...args) => {
47		
48		let result = undefined
49		let success = undefined
50		let code = source
51		
52		result = {success, code} = func(code, ...args)
53		if (!success) {
54			result.success = true
55			result.snippet = ""
56		}
57		
58		return result
59	}
60	
61	EAT.list = (...funcs) => (source, ...args) => {
62		
63		// Buffers
64		let success = undefined
65		let code = source
66		
67		// Head
68		let headResult = undefined
69		const headFunc = funcs[0]
70		headResult = {success, code} = headFunc(code, ...args)
71		if (!success) return {...headResult, code: source}
72		
73		// Tail
74		let tailResult = undefined
75		const tailFuncs = funcs.slice(1)
76		if (tailFuncs.length == 0) return headResult
77		tailResult = {success, code} = EAT.list(...tailFuncs)(code, ...args)
78		tailResult.snippet = headResult.snippet + tailResult.snippet
79		return tailResult
80		
81	}
82	
83	EAT.or = (...funcs) => (source, ...args) => {
84	
85		for (const func of funcs) {
86		
87			let result = undefined
88			let success = undefined
89			let code = source
90			
91			result = {success, code} = func(code, ...args)
92			if (success) return result
93		}
94		
95		const success = false
96		const code = source
97		const snippet = undefined
98		return {success, snippet, code}
99	}
100	
101	EAT.fail = (source) => ({success: false, snippet: undefined, code: source})
102	
103	//====================//
104	// In-Built Functions //
105	//====================//	
106	EAT.string = (string) => (source) => {
107		const success = source.slice(0, string.length) == string
108		const snippet = success? string : undefined
109		const code = success? source.slice(string.length) : source
110		return {success, snippet, code}
111	}
112	
113	EAT.regexp = EAT.regExp = EAT.regex = EAT.regEx = (regex) => (source) => {
114		const fullRegex = new RegExp("^" + regex.source + "$")
115		
116		let i = 0
117		while (i <= source.length) {
118			const snippet = source.slice(0, i)
119			const success = fullRegex.test(snippet)
120			if (success) {
121				const code = source.slice(snippet.length)
122				return {success, snippet, code}
123			}
124			i++
125		}
126		
127		const success = false
128		const snippet = undefined
129		const code = source
130		return {success, snippet, code}
131		
132	}
133	
134	EAT.space = EAT.string(" ")
135	EAT.tab = EAT.string("	")
136	EAT.newline = EAT.newLine = EAT.string("\n")
137	
138	EAT.gap = EAT.many (
139		EAT.or (
140			EAT.space,
141			EAT.tab,
142		)
143	)
144	
145	EAT.whitespace = EAT.whiteSpace = EAT.many (
146		EAT.or (
147			EAT.space,
148			EAT.tab,
149			EAT.newline,
150		)
151	)
152	
153	EAT.emptyLine = EAT.list (
154		EAT.maybe(EAT.gap),
155		EAT.newline,
156	)
157	
158	EAT.emptyLines = EAT.many(EAT.emptyLine)
159	
160	EAT.name = EAT.list (
161		EAT.regexp(/[a-zA-Z_$]/),
162		EAT.many(EAT.regex(/[a-zA-Z0-9_$]/))
163	)
164	
165	EAT.margin = EAT.or (
166		EAT.many(EAT.tab),
167		EAT.many(EAT.space),
168	)
169	
170	EAT.line = EAT.many(EAT.regex(/[^\n]/))
171}